Definitely a great place to stay!!
My wife and I just returned from a 3 day visit to Yemen. We stayed each night at the Taj Sheba and found the hotel its staff to be great! The rooms were clean and pleasant, the food was excellent as was the service (well, except for slowness refilling coffee cups).
The hotel has a very nice looking swimming pool, although we didn't personally try it. From the hotel it is a reasonable walk to the old souks, but you do have to cross the busy highway near the hotel. I didn't notice if there was internet connection, but the TV worked great.
Security seemed appropriate and we felt confortable and safe there.
We hope to return to Sana'a and will definitely stay at the Taj!!!